Rock-drill.



No, sa|,5o4. Patanfed Aug. 27, 190|. c. HuLTuulsT.

BUCK DRILL.

(Application filed Apr. 13, 1901.)

(Ilo Model.)

WTNESSES:

( @7d m, W ATTO NEI/J' .UN TTI-3D STATES PATENT OFFTCE.

OIIARLEY HULTQUIST, OF JEROME, ARIZONA TERRITORY.

ROCK-DRILL.

SPECIFICATION formingpart of Letters Patent No. 681,504, dated August 27, 1901.

Application iled April 13, 1901. Serial No. ,645. (No model.)

T0 LZZ whom t may concern:

Be it known that I, CHARLEY HULTQUIST, a citizen of the United States, residing at .I erome, county of Yavapai, Arizona Territory, have invented an Improvement in Rock- Drills; and I hereby declare the following to be a full, clear, and exact description of the same.

My invention relates to improvements in rock-drilling machines actuated by steam or like medium.

The object of my invention is to effect a reduction in the amount of power necessary to operate the drill and to furnish a machine of few parts and those parts of simple construction.

It consists, essentially, of a double steamchest disposed approximately the length of the drill-cylinder, a double piston-valve reciprocable in said chests, short steam-ports entering from either of the chests directly into the cylinder,pone of said chests having a slightly-larger interior diameter than the other, and the piston-valve having its diameters of corresponding size, whereby the starting of the machine is facilitated.

It also comprises details which will be more fully hereinafter set forth.

Having reference to the accompanying drawings, Figure 1 is a longitudinal section through the drill. Fig. 2 is a bottom view of the steam-chest.

A represents the shell of a drill, having a cylinder 2, in which the drill-piston 3 reciprocates.

B represents my improved steamchest, which is of approximately the same length as the cylinder. From either end of this chest there enter the short ports 4. into the cylinder. A valve-rod 5 is reciprocable in the chest and is provided at each end with the double pistons 6 6', which control the admission to and exhaust from the cylinder. Steam is admitted to the chest through the opening 7. In reality there are two chests or valve-chambers b and b', one at each end of the cylinder, having a common feed pipe or trunk, through which the piston valve-rod reciprocates. Each of these chambers is provided with two smaller ports 8 and 9 in rear of the pistons 6 and 6', respectively, and these ports are connected by a passage 10, Fig. 2. These passages l0 also have continuations 11 and 11, which are adapted alternately to open yinto the annular channel 12, formed by a cutdown portion on the piston 3, during the reciprocation of the latter. The ports 9 are minute in comparison with the openings 8, Fig. 2, as the former are intended only to admit steam enough into the chambers b or b behind the valves 6 to reciprocate the pistonvalve, while the ports 8 correspond in size with the passages 10 and l1 or 11', so as to permit rapid exhaust of steam from this portion of the valve-chambers. A small quantity of steam is always escaping from the ports 9 and is either passing behind the valves 6, as just stated, or is mingling with the exhaust from behind these valves. The cylinder-exhaust takes place through the ports 13. The valves 6 and 6 reciprocate between the ports 8 and 13 and 13 and 9, respectively. Access is had to the piston-valves by removing either of the plugs 14.

The operation of the machine would be as follows, presuming the valve and drill-piston to be in the position shown in Fig. 1 1'. e., at the beginning of the stroke: The piston 3 has closed the passage 11 and uncovered the passage 1l. Steam has entered that portion of the chest b behind the valve 6 through the port 9, channel 10, and port 8 to drive the piston valve forward. Meantime exhaust from behind the valve 6 in chamber b has taken place into the channel 12. The forward stroke 0f the drill reverses the action of the piston-valve.

In order to overcome any difficulty in starting by reason of the valves overlapping the ports 4, I have made one of my chambers, as b', of a slightly-larger interior diameter than the other. The valves fitting the chamber b' are correspondingly of larger diameter, so that when steam is admitted into the chest a greater exposed surface is offered by this end of the valve to the action of the steam, and, other things being equal, the piston.- valve is thrown off balance and moved toward the end of the chamber b.

By constructing my steam-chest as shown I do away with thelong and crooked ports usual in these machines, reducing friction and delivering hotter and drier steam consequently to the cylinder, and experience shows an eiectual saving of no less than twelve per cent. in the amount of propelling medium necessary to drive the drill.

The advantage of connecting the valvechambers direct with the steam-chest is that the steam having had no time to cool or condense is far more effective in its action' on the piston-valve, and consequently less steam is necessary than if it had first gone into the cylinder and had been delivered thence to the valve-chambers.

Having thus described my invention, what I claim as new, and desire to secure by Letters Patent, is-

l. The combination in a rock-drill of a cylinder, a drill-piston reciprocable therein, a steam-chest having a valve-chamber at each end and a steam-entrance intermediate of said chambers and common to both chambers, ports connecting each valve-chamber directly with the cylinder, a valve-rod and a double valve at each end thereof, said valves operating in their chambers and controlling the admission of steam to and the exhaust from the cylinder.

2. The combination in a rock-drill of a cylinder and a piston reciprocable therein, a chest extending approximately the same length as the cylinder and having a valvechamber at each end said chest having a propellingmedium inlet intermediate of the chambers and common to both chambers, separate inlet and exhaust ports for each valve-chamber, connecting directly with the cylinder, a valve-rod operating in the chest and a double valve at each end of said rod, and controlling'the admission of the propelling medium to and the exhaust from the cylinder, and connections of the ports for permitting the propelling medium to pass from front to rear of the valves to actuate the valve-rod.

3. In a rock drill, a steam-chest comprising two valve-chambers, each having separate feed and exhaust ports, one of said chambers of slightly-larger interior diam eter than the other, said chest forming a connection between said chambers, and having a steaminlet common to both chambers, a piston-rod therein and having a double valve at each end, said valves of a diameter corresponding with their respective chambers.

4. The combination in a rock-drill of a cylinder, a piston movable therein, a steam-chest having a chamber at each end of the cylinder, a double valve in each chamber, connections of these valves whereby they are moved in unison, ports connecting said chambers and I cylinder, exhaust-ports in each chamber, an opening at one end of each of said chambers, a smaller opening at the other end of each of said chambers, said double valve reciprocable between these respective openings, connections of the latter in each chamber, and means whereby steam is alternately exhausted through said connections by the alternate reciprocations of the piston in the cylinder.

5. The combination in a rock-drill of a cylinder, a piston therein, a steam-chest having two chambers connected by a trunk, one of said chambers of smaller interior diameter than the other, a piston-rod movable in said trunk and having a double valve at each end whereby the admission to and exhaust from the cylinder is controlled, the diameter of said valves corresponding to the diameters of their respective chambers, an opening at the outer end of each of said chambers, a smaller opening at the adjacent ends of said chambers, connections of said openings whereby the propelling medium may pass from one side of one of said valves to the other, and a passage leading from each of said last-named connections through Which exhaust of propelling medium from said connections may take place.

In witness whereof I hand. Y

CHARLEY HULTQUIST.

have hereunto set my Vitnesses:

SAMUEL E. GARRETT, FERDINAND M. HEFTY. 

